It is possible that a Covid-19 booster shot will be needed again this fall.
U.S. officials have indicated that coronavirus cases may increase in colder months. Scientists are still evaluating whether another dose is necessary.
Moderna or Pfizer BioNTech will get their way. The next round of vaccines could contain a new formulation targeting the supercontagious Omicron variant or possibly two strains.
Moderna Chief Medical Officer Dr. Paul Burton stated that the world will need a new Covid vaccine in fall. He said it's "tuned for the right combination" of variants.
In the United States, the number of Covid-fueled cases is continuing to drop. The coronavirus will likely remain. Covid could become a seasonal virus similar to influenza. Dr. Rochelle Walsky, director at the Centers for Disease Control and Prevention and other top experts in health, suggests that this is possible.
Viruses can keep mutating
Although no one knows the prevailing variant, scientists at the World Health Organization suggest that vaccines need to be updated in order to protect against serious disease and death.
Pfizer and Moderna still use booster shots that target the coronavirus original form.
Moderna believes that the dominant strain in this fall could be one we are all familiar with: omicron or delta, or a descendant.
Burton stated that "Delta" and "omicron" are still present. These variants will now be going into the Southern Hemisphere where they'll either continue proliferating or may mutate.
Moderna and Pfizer both test new micron-specific shots. They have begun trials and could be available by fall.
Moderna is also working on a bivalent vaccine, which combines an omicron specific vaccine with its original formula in one shot. Burton stated that the bivalent vaccine, which Moderna calls its "ideal candidate for the fall," will be available in human trials within the next few weeks.
John Moore, a professor at Weill Cornell Medical College of Microbiology and Immunology, stated that there is no guarantee that any new vaccines in development will work as expected.
He pointed out a February animal study that showed that an omicron-specific booster shot might not be as effective as the other boosters. The study was done by scientists from the National Institute of Allergy and Infectious Diseases. They examined blood samples taken from primates who had received a shot that contained omicron, or the original coronavirus.
Moore stated that the new shots might not be necessary, noting that the existing vaccine provides protection against severe diseases, hospitalization, and death. Moore was particularly skeptical about the bivalent vaccine, as he stated that there have never been two dominant variants of Covid.
Moderna and Pfizer are making "a guess," he stated, adding that scientists might not know the exact shot for several months.
Moore stated, "This is when predicting future outcomes becomes really, really crappy."
Is FDA clearance possible faster?
Moderna and Pfizer would need to present compelling reasons why they believe new shots are better than existing vaccines. This is according to Dr. Celine Gounder of NYU Langone Health.
"We haven't updated vaccines because we've found that by giving just an additional dose, you can increase the antibody titers. She said.
For review by the Food and Drug Administration, drugmakers will need to submit data.
FDA previously stated that modified Covid vaccines for new and emerging variants of omicron may be approved without lengthy clinical trials. It is not clear if the FDA would grant the same exemption for a bivalent vaccine.
Norman Baylor, President and Chief Executive of Biologics Consulting and a former Director of FDA's Office of Vaccine Research and Review, stated that the agency could issue an emergency use authorization for a bivalent vaccination if there is a need.
He stated that he hopes federal regulators will give drug manufacturers information on the data they need. Otherwise, it would be a waste of resources if everyone just does clinical trials to see what sticks.
Baylor stated that Moderna and Pfizer have licensed products. The FDA may say, "Let's do an inferiority trial against your licensed product." Noninferiority studies examine whether a new treatment is more effective or less harmful than the active treatment.
According to Dr. Jesse Goodman, Georgetown University's former chief FDA vaccine officer, regulators should approve if there is evidence of an advantage and that it is safe.
Baylor and Gounder both stated that a new vaccine would definitely complicate manufacturing. The new vaccines won’t help if they aren’t mass-produced.
Moderna's Burton admitted that it is technically more difficult to manufacture a bivalent vaccine because it involves the combination of two mRNAs in one lipid nanoparticle. He said that the company's mRNA-based cancer vaccine candidate can combine 30 antigens in one shot.
He stated that the company was confident it can make a convincing case to FDA using wide-ranging data from its original vaccine and its omicron specific shot, as well as the bivalent vaccines that it has tested or will test.
Who will be in need of another booster?
According to Dr. Paul Offit, a pediatric vaccine expert at Children's Hospital of Philadelphia, if a new booster is approved, it's unlikely that all Americans will need the shot.
He said that the protection against death, severe illness, and hospitalization provided by the first two doses mRNA vaccines appears to still be working in healthy individuals.
Offit stated that an additional dose may be beneficial for those in nursing homes, elderly people, and those with high-risk medical conditions.
Gounder agreed with Gounder that people at high risk should be given the extra shot, particularly if it provides greater protection. She was concerned that the introduction of a new vaccine might increase vaccine hesitancy, particularly among those who are not willing to get them.
Michael Osterholm (director of the University of Minnesota’s Center for Infectious Disease Research and Policy) suggested that health care providers could give new vaccines in the fall and possibly other vaccines going forward.
His center is currently working on a "roadmap for pan-coronavirus vaccinations", which will detail the research, development, financing, and use of the shots.
Scientists monitor the influenza strains continuously and each year select three to four to include in the flu vaccine.
Baylor of Biologics Consulting said that it is too early to predict which coronavirus variants will prevail. However, there is growing evidence that existing vaccines aren't as effective against the virus. He suggested that it might be time to upgrade vaccines to target the most prevalent variant.
"It's quite good with the original, but could there be better?" He said. "I don’t know until we see the data."
